Text.cpp

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#include <sourcepp/parser/Text.h>
 
#include <algorithm>
#include <cctype>
 
#include <BufferStream.h>
 
using namespace sourcepp;
 
const parser::text::EscapeSequenceMap& parser::text::getDefaultEscapeSequences() {
    static const EscapeSequenceMap defaultEscapeSequences{
            {'\'', '\''},
            {'\"', '\"'},
            {'?',   '?'},
            {'\\', '\\'},
            {'a',  '\a'},
            {'b',  '\b'},
            {'f',  '\f'},
            {'n',  '\n'},
            {'r',  '\r'},
            {'t',  '\t'},
            {'v',  '\v'},
    };
    return defaultEscapeSequences;
}
 
const parser::text::EscapeSequenceMap& parser::text::getDefaultEscapeSequencesOrNone(bool useEscapes) {
    static const EscapeSequenceMap noEscapeSequences{};
    return useEscapes ? getDefaultEscapeSequences() : noEscapeSequences;
}
 
bool parser::text::isNewLine(char c) {
    return c == '\n' || c == '\r';
}
 
bool parser::text::isNewLine(std::string_view str) {
    return std::ranges::all_of(str, [](char c) { return isNewLine(c); });
}
 
bool parser::text::isWhitespace(char c) {
    return c == ' ' || c == '\a' || c == '\f' || c == '\t' || c == '\v' || isNewLine(c);
}
 
bool parser::text::isWhitespace(std::string_view str) {
    return std::ranges::all_of(str, [](char c) { return isWhitespace(c); });
}
 
bool parser::text::isNumber(char c) {
    return std::isdigit(c);
}
 
bool parser::text::isNumber(std::string_view str) {
    return std::ranges::all_of(str, [](char c) { return isNumber(c); });
}
 
std::string parser::text::convertSpecialCharsToEscapes(std::string_view str, const EscapeSequenceMap& escapeSequences) {
    // Reverse escape sequences map (assume that it's bidirectional)
    EscapeSequenceMap specialSequences;
    for (const auto& [normal, special] : escapeSequences) {
        specialSequences[special] = normal;
    }
 
    std::string out;
    for (int i = 0; i < str.length(); i++) {
        if (specialSequences.contains(str[i])) {
            out += '\\';
            out += specialSequences[str[i]];
        } else {
            out += str[i];
        }
    }
    return out;
}
 
std::string parser::text::convertEscapesToSpecialChars(std::string_view str, const EscapeSequenceMap& escapeSequences) {
    std::string out;
    for (int i = 0; i < str.length(); i++) {
        if (!escapeSequences.empty() && str[i] == '\\' && i < str.length() - 1) {
            auto n = str[i + 1];
            if (escapeSequences.contains(n)) {
                out += escapeSequences.at(n);
            } else {
                out += str[i];
                out += str[i + 1];
            }
        } else {
            out += str[i];
        }
    }
    return out;
}
 
void parser::text::eatWhitespace(BufferStream& stream) {
    while (isWhitespace(stream.read<char>())) {}
    stream.seek(-1, std::ios::cur);
}
 
void parser::text::eatSingleLineComment(BufferStream& stream) {
    while (!isNewLine(stream.read<char>())) {}
}
 
void parser::text::eatMultiLineComment(BufferStream& stream, std::string_view multiLineCommentEnd) {
    while (!std::ranges::equal(stream.read_span<char>(multiLineCommentEnd.length()), multiLineCommentEnd)) {
        stream.seek(-static_cast<int64_t>(multiLineCommentEnd.length() - 1), std::ios::cur);
    }
}
 
void parser::text::eatWhitespaceAndSingleLineComments(BufferStream& stream, std::string_view singleLineCommentStart) {
    return eatWhitespaceAndComments(stream, singleLineCommentStart, "");
}
 
void parser::text::eatWhitespaceAndMultiLineComments(BufferStream& stream, std::string_view multiLineCommentStart) {
    return eatWhitespaceAndComments(stream, "", multiLineCommentStart);
}
 
// NOLINTNEXTLINE(*-no-recursion)
void parser::text::eatWhitespaceAndComments(BufferStream& stream, std::string_view singleLineCommentStart, std::string_view multiLineCommentStart) {
    eatWhitespace(stream);
 
    if (!singleLineCommentStart.empty()) {
        if (std::ranges::equal(stream.read_span<char>(singleLineCommentStart.length()), singleLineCommentStart)) {
            eatSingleLineComment(stream);
            eatWhitespaceAndComments(stream, singleLineCommentStart, multiLineCommentStart);
            return;
        }
        stream.seek(-static_cast<int64_t>(singleLineCommentStart.length()), std::ios::cur);
    }
 
    if (!multiLineCommentStart.empty()) {
        if (std::ranges::equal(stream.read_span<char>(multiLineCommentStart.length()), multiLineCommentStart)) {
            eatMultiLineComment(stream);
            eatWhitespaceAndComments(stream, singleLineCommentStart, multiLineCommentStart);
            return;
        }
        stream.seek(-static_cast<int64_t>(multiLineCommentStart.length()), std::ios::cur);
    }
}
 
bool parser::text::tryToEatChar(BufferStream& stream, char c) {
    if (stream.peek<char>() != c) {
        return false;
    }
    stream.skip();
    return true;
}
 
std::string_view parser::text::readStringToBuffer(BufferStream& stream, BufferStream& backing, std::string_view start, std::string_view end, const EscapeSequenceMap& escapeSequences) {
    const auto startSpan = backing.tell();
 
    bool stopAtWhitespace = true;
    char c = stream.read<char>();
    if (start.find(c) != std::string_view::npos) {
        stopAtWhitespace = false;
    } else {
        backing << c;
    }
 
    for (c = stream.read<char>(); (stopAtWhitespace && !isWhitespace(c)) || (!stopAtWhitespace && end.find(c) == std::string_view::npos); c = stream.read<char>()) {
        if (!escapeSequences.empty() && c == '\\') {
            auto n = stream.read<char>();
            if (stopAtWhitespace && isWhitespace(n)) {
                break;
            }
            if (escapeSequences.contains(n)) {
                backing << escapeSequences.at(n);
            } else if (!stopAtWhitespace && end.find(n) != std::string_view::npos) {
                break;
            } else {
                backing << c << n;
            }
        } else {
            backing << c;
        }
    }
 
    backing << '\0';
    return {reinterpret_cast<const char*>(backing.data()) + startSpan, backing.tell() - 1 - startSpan};
}
 
std::string_view parser::text::readUnquotedStringToBuffer(BufferStream& stream, BufferStream& backing, const EscapeSequenceMap& escapeSequences) {
    return readStringToBuffer(stream, backing, "", "", escapeSequences);
}
 
std::string_view parser::text::readUnquotedStringToBuffer(BufferStream& stream, BufferStream& backing, std::string_view end, const EscapeSequenceMap& escapeSequences) {
    const auto startSpan = backing.tell();
 
    for (char c = stream.read<char>(); !isWhitespace(c) && end.find(c) == std::string_view::npos; c = stream.read<char>()) {
        if (!escapeSequences.empty() && c == '\\') {
            auto n = stream.read<char>();
            if (escapeSequences.contains(n)) {
                backing << escapeSequences.at(n);
            } else if (isWhitespace(n) || end.find(n) != std::string_view::npos) {
                break;
            } else {
                backing << c << n;
            }
        } else {
            backing << c;
        }
    }
 
    backing << '\0';
    return {reinterpret_cast<const char*>(backing.data()) + startSpan, backing.tell() - 1 - startSpan};
}